Deepwater oil production is a rapidly growing segment of the oil industry. As the number of deepwater installations increase, so do the problems with maintaining sub-sea fluid transport systems. Sub-sea equipment, including pipelines, are becoming clogged with precipitates of the production fluids, including waxes, asphaltenes, hydrates (gas/water ices) and scale (e.g. calcium carbonate). Similarly, production tubing in producing wells can develop flow-restricting deposits, usually of the asphaltene type. There are significant problems because of the enormous cost of lost production, and because of the very large expenses involved in identifying and replacing, or bypassing, the constricted or blocked sections of pipe. The industry refers to these and related issues as “Flow Assurance”. In 1999 Welling and Associates, having conducted a world-wide study of 110 oil and gas companies, found that flow assurance was the most important technical challenge facing the oil and gas industry. Connective pipelines, manifolds and risers can total hundreds of kilometers (i.e. hundreds of miles) in length, and operate at water depths of up to approximately 3,000 m (approximately 10,000 ft). Maintenance over these distances and at these depths is very costly. Deposits often occur in one region of a pipe, spanning many meters (many feet), but not extending over the entire pipe length. The chemistry of formation of the different types of deposit is at least partially understood. Gas cut, flow rate, and temperature at depth are all relevant factors. This knowledge facilitates identification of locations where deposits can be expected to occur. However, the first indication that deposition is occurring is usually a reduction in flow rate, which is too late.
Thus, the industry needs a cost-effective method for detecting and characterizing solids deposits inside oilfield production pipelines to improve flow assurance. Currently, no cost-effective methods are available.